Oysters for the Future: The Value of Science-Based Management in the Oyster Fishery1

The eastern oyster (Crassostrea virginica) provides many important functions in coastal environments, from serving a crucial role in the estuary’s food web to improving water quality for beachgoers and wildlife. Oysters are also a popular food choice for people—at times the commercial industry landings value has topped $8 million annually in Florida. This publication is one in a series that highlights some of the key ecological and human factors important to the long-term sustainability of this valuable fishery.

Figure 1.

Understanding the factors impacting juvenile oyster recruitment in an estuary is a critical research need.

Credit:

Keith Kolasa, Florida Sea Grant

[Click thumbnail to enlarge.]

Good Science is not Always Easy, but it is Always Valuable

The sentiment that a natural resource issue has been “studied to death” and “something just needs to be done” is often heard in discussions about restoring depleted resources. Frustrations run high and people who are impacted are sometimes desperate for relief. The following information summarizes the value of science-based management and why “just doing something” is not the best option in the long run.

The key to “good science” lies in a study procedure that accurately links cause and effect and eliminates as many unknowns as possible related to the questions you want to answer. The scientific method is designed to do this through the following steps:

Asking a question

Doing background research

Constructing a hypothesis

Testing the hypothesis by doing an experiment

Analyzing data to draw a conclusion

Communicating the results

Figure 2.

Sound scientific work informs good policy and leads to solid fisheries management for the long term.

Credit:

Florida Sea Grant

[Click thumbnail to enlarge.]

Neglecting any of these steps places study results in question. Another aspect to consider is the time frame it takes to do research and the time frame for which study results will be valid. Scientists are usually looking at a snapshot of time with their data. The dynamic nature of nature itself requires an honest assessment by the scientist of how valid results may be as time passes. Some research focuses on well-defined questions and answers. Likewise, the importance of long-term monitoring should never be undervalued.

Historic benefits of oyster research: Many things we know about oysters are a result of scientific study. Specialists in the areas of microbiology, ecology, parasitology, pathology, and many other disciplines have contributed to our understanding in the following areas:

Oyster biology and mortality facts: Through scientific research various disease-causing organisms, predators, and parasites have been identified as the culprits in historic oyster declines. This goes hand in hand with scientific understanding gained by studying the oyster life cycle, food and feeding behavior, spawning and juvenile oyster “spat-set” requirements, and oyster growth patterns under various conditions.

Oysters providing ecosystem services: Scientists have demonstrated that an oyster filters as much as 50 gallons of water per day, which removes some excess nitrogen and other pollutants from the water that may help to fuel harmful algal blooms. Oyster reefs also provide habitat for other filter feeders such as mussels, barnacles, and tunicates that add dramatically to filtering capacity. The structure of the reef itself traps fine silt from runoff and reduces its resuspension. These factors are no substitute for sound storm and waste water management policies, but they do improve water quality and clarity.

Oysters as food: Food scientists have discovered that oysters and mollusks in general are high in zinc, an important mineral in many human metabolic processes. Pathologists have studied health risks associated with a product that is traditionally eaten raw and discovered the specific temperature requirements that will limit harmful bacteria growth. This has led to important harvest, storage, and transport procedures that minimize risks for consumers.

Figure 3.

Local harvesters participate in restoration efforts in an Apalachicola Bay project.

Credit:

Erik Lovestrand, UF/IFAS Extension/Florida Sea Grant

[Click thumbnail to enlarge.]

Important current research topics: In light of a recent historic fishery collapse in Apalachicola Bay, where 90% of Florida’s oysters were traditionally harvested, intensive research and restoration efforts are ongoing. Due to the magnitude and importance of this oyster fishery, many different professionals are participating in research related to water quality and freshwater inflow, hard-bottom substrate suitability, the amount of substrate material necessary for restoration efforts, oyster shell parasites, oyster spat recruitment and survival, and oyster population surveys. All of these studies fill information gaps that allow resource managers to make better choices regarding management options.

Protection of study sites: Researchers need to account for many variables in field studies. When a variable that affects the results cannot be identified or measured, results may not be accurate. Pinpointing natural factors and keeping track of them is challenging enough, but there is one other factor that can sabotage an important study: unaccounted human activity on a research site.

Shellfish research often requires counts to determine the effect of management strategies. It is crucial that harvesters support valid science by protecting the sanctity of study sites. This allows researchers to accurately measure oyster population responses. Illegal harvesting on study sites will produce bad data, and bad data means incorrect assumptions. Policy decisions on the future of the oyster fishery must be based on solid science. This provides for the most effective and efficient use of public resources needed for the recovery of this fishery.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.